<!DOCTYPE html>
<html>
  <head>
  <meta charset="utf-8">
  <title>Hello World</title>
  <!-- 开发环境版本，包含了有帮助的命令行警告 -->
  <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
  </head>
  <body>
 <div id="app">
   <p>{{ score }}</p>
<input v-model="score"> 
<div v-if="score>=90">优秀</div>
<div v-else-if="score>=80&&score<90">良好</div>
<div v-else-if="score>=70&&score<80">中等</div>
<div v-else-if="score>=60&&score<70">及格</div>
<div v-else>不及格</div>
</div>

 <script>
   new Vue({
     el: '#app',
     data: {
       score: 100
     }
   })
 </script>
  </body>
</html>